<!DOCTYPE html>
<html lang="en">
  <head>
    <meta charset="UTF-8" />
    <meta name="viewport" content="width=device-width, initial-scale=1.0" />
    <title>Document</title>
  </head>
  <body>
    <input
      type="text"
      id="elInput"
      class=""
      name="uname"
      username="jack"
      age="20"
    />
    <script>
      const elInput = document.getElementById("elInput");

      elInput.username = "jack";
      elInput.age = 20;
      elInput.say = function () {};

      console.log(elInput.username);
      console.log(elInput.age);
      console.log(elInput.say);
      console.dir(elInput);
    </script>
  </body>
</html>
